Judging by some of the heavy action in the world of biotechnology, one could easily conclude the industry is going to the dogs. Or cats, maybe.

There are startups named Nexvet and VetDC, CanFel Therapeutics (as in canine and feline), and Fetch Pharma.

It’s a new example of pack behavior: Entrepreneurs with pedigrees from companies such as Genentech and Amgen are turning their attention to pets. They hope to develop the same kinds of innovative drugs for dogs and cats that have revolutionized the treatment of diseases such as cancer and arthritis in people.

“We’ve been drugging ourselves for a long time and more recently we’ve been drugging our kids,” said Oleg Nodelman, an investor in and director of Kindred Biosciences, one of the new companies. “Why shouldn’t our pets have access to medicine?”

They do already. Many of the big pharmaceutical companies have long had veterinary drug divisions. Eli Lilly’s animal division, Elanco, for instance, sells the company’s Prozac antidepressant under the name Reconcile to treat canine separation anxiety.

The new entrepreneurs say they will be more nimble and do what the big companies are not doing, just as the early human medicine biotech companies did.

The big companies focus more on livestock — edible animals as opposed to petable animals, said Dr. Steven St. Peter, chief executive of Aratana Therapeutics, a pet-biotech company. Their offerings for pets are mainly vaccines and treatments for fleas, ticks and worms.

The new companies hope instead to treat diseases such as cancer and arthritis. Many are trying to develop monoclonal antibodies, proteins made in living cells. Such antibodies, such as Humira for rheumatoid arthritis and Herceptin for breast cancer, are huge sellers in human medicine but have had almost no role in animal health.

“I was really a little struck by the fact that the biotechnology industry didn’t really participate in animal health at all,” said St. Peter, who was a life-sciences venture capitalist before co-founding Aratana. “There was this very large industry that was ripe for innovation.”

Investors seem to be biting, spurred in part by the interest generated by the huge initial public offering in early 2013 of Pfizer’s animal-drug division, now called Zoetis. Since then, Aratana and Kindred have gone public, along with Phibro, which develops drugs for livestock, and Parnell, which sells livestock and pet drugs.

The new companies say the time is right because people increasingly view pets as family and are willing to spend thousands of dollars to treat a sick animal. Pets can get chemotherapy, knee surgery and transplants.

Americans spent nearly $56 billion on pets in 2013, up 45 percent from 2006, according to the American Pet Products Association. Of that amount, veterinary care, which includes prescription drugs, accounted for $14.4 billion, up more than 50 percent from 2006.

Adapting therapies

There are drugs for people that can be adapted to treat the animal versions of arthritis, cancer, obesity, diabetes, Alzheimer’s and various psychological problems.

Some experts say the new companies, which have yet to commercialize any products, might be barking up the wrong tree.

“There are not a lot of unmet needs that are out there in the veterinary drug field,” said Bob Fountain of Fountain Agricounsel, a consulting firm in animal health. “Those who have tried to apply principles from the human market to animal health have had to have some lessons learned.”

One challenge could be cost. Antibodies such as Herceptin and Humira cost tens of thousands of dollars a year. The pet-drug executives say they can get the cost down to several thousand dollars a year, in part because pets need smaller doses.

Even that is likely to be too much for many consumers. Only a few percent of American pet owners have health insurance for their animals.

Even a big-selling animal drug might have sales of about $100 million a year, far less than the billions for a human blockbuster. But animal drugs can also be developed far more cheaply and quickly — for $10 million or less and in only a few years, executives say.

Kindred, for instance, hopes to apply for approval of its first drug by the end of the year, barely two years after the company started.

The drug is a beef-flavored chewable version of diacerein, a generic drug used in Europe but not the United States to treat arthritis in people. European regulators are moving to restrict use of the drug because of safety, but Kindred says that worrisome side effects, such as liver damage, should occur less frequently in dogs.

Kindred was founded by Richard Chin, a Genentech alumnus who later ran OneWorld Health, a nonprofit developing drugs for neglected diseases in poor countries.

Not always same use

In some cases, drugs for humans can be used directly in animals. But in other cases they cannot. For instance, some pain relievers such as ibuprofen cause severe side effects in cats.

Monoclonal antibodies developed for people would cause immune reactions in animals. Nexvet, a privately held Australian company that raised $31.5 million from U.S. investment funds, has a method to “peticize” antibodies, just as antibodies developed in mice are “humanized” for use in people.

VetDC was founded to take advantage of another trend: Pharmaceutical companies increasingly are testing their drugs on pets to get an early read on how the drug might work in people.

For instance, Gilead Sciences stopped work on a drug it was developing to treat lymphoma in people. But by then, studies had shown “beautiful data in people’s pets,” said Steven Roy, a former Amgen executive who runs VetDC. So VetDC is now developing that drug for lymphoma in dogs.

Consolidation in the new industry has begun. Aratana, which means “new” in Japanese, has acquired two other startups, Vet Therapeutics, which was developing antibodies, and Okapi, which was developing antiviral drugs.

Aratana has conditional regulatory approval for two antibodies to treat dog lymphoma. The drugs have the same mechanisms of action as the human drugs Rituxan and Campath, respectively. Aratana plans to start marketing one in October.

If the startups succeed, it might not be too long before established biotech companies form their own animal divisions. At least one company, Sorrento Therapeutics, recently said it would do this.